Determination of the position of the observed peaks in polarization (top) and the maximum wavelength at which signal is still above noise (bottom) for all the data available since 2013. The gray horizontal line marks the average wavelength of the intensity line center. The blue and red lines mark the chosen values of V_max = 60 kms⁻¹ and V_* = 40 kms⁻¹ respectively. Wavelengths are given in kms⁻¹ in the barycentric reference. Neo-Narval data start from day 2700. Noise is defined and measured as the standard deviation of the polarization signal at wavelengths beyond 100 km s⁻¹ of the center of the spectral line. Typical noise values are below 10⁻⁴ of the continuum intensity.